#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
#include<string.h>

int  is_palindrom_string(char arr[])
{
	int n = strlen(arr);
	char* left = arr;
	char* right = arr + n - 1;

	while (left < right)
	{
		if (*right != *left)
			return 0;
		left++;
		right--;
	}
	return 1;
}
int main()
{
	char arr[31];
	scanf("%[^\n]s", arr);
	int ret = is_palindrom_string(arr);
	if (ret == 1)
		printf("yes\n");
	else
		printf("no\n");
	return 0;
}